Study On Mechanical Properties Of Steel Polyurethane Sandwich Panel Under Impact Loading

The steel polyurethane sandwich panel is a sandwich panel composed of polyurethane elastomer as core layer and steel sheet as panel.As a new type of sandwich structure,this type of sandwich panel has attracted attention because of its light weight,high strength and convenient processing.Since the core material polyurethane elastomer is a polymer,it can be quickly restored to its original state after being deformed by force,which makes the sandwich panel structure have good energy absorption,noise reduction and impact resistance.It has been widely used in ship structure manufacture,repair and bridge deck construction.In these applications,steel polyurethane sandwich panels tend to be damaged and destroyed by some impact loads.Therefore,it is of great significance to study the mechanical properties of steel polyurethane sandwich panels under impact load.In this paper,the combination of experimental and numerical simulation methods are used to study the deformation mechanism and failure mode of steel polyurethane sandwich panels under impact load.The main research contents are as follows:(1)Based on the experimental study on the static compression and tensile mechanical properties of polyurethane elastomers,the stress-strain curves of the materials under different loading conditions are obtained,and the deformation mechanism of the materials during tensile and compression is studied.(2)The dynamic mechanical properties of polyurethane elastomers are studied by using split Hopkinson pressure bar.For the dispersion phenomenon of incident wave waveform in the process of Hopkinson pressure bar test,vacuum sealer is used as waveform shaper,and its shaping effect and influencing factors are analyzed.In view of the radial inertia effect of soft materials in dynamic testing,the test results of polyurethane elastomer hollow specimens and solid specimens were studied,and the polyurethane elastomer hollow specimens were used to obtain materials at different strain rates.The relationship between stress and strain curves.Combining the results of static compression experiments,the relationship between yield strength and strain rate of polyurethane elastomer is obtained.(3)The penetration test system of steel polyurethane sandwich plate is established,and the impact resistance of steel polyurethane sandwich plate is experimentally studied by spherical projectile.The failure mode of the sandwich panel under different initial velocity projectiles is analyzed,the displacement variation law of the sandwich panel is studied,and the deformation and damage form of the sandwich panel are discussed.The deformation of the sandwich panel under the impact of the projectile is recorded by a high-speed camera.In the process,the variation of the energy absorption effect of the sandwich panel and the initial velocity of the projectile is analyzed,and the ballistic limit of the steel polyurethane sandwich panel is given.(4)The ABAQUS finite element simulation software is used to simulate the process of projectile penetration into steel polyurethane sandwich panels.The deformation mechanism and failure process of steel polyurethane sandwich panels under different velocity projectiles are studied,and the velocity curve of the projectiles is given.